In 1992 (the time of Grand Theft Auto: San Andreas), they had territory in Liberty City after Sonny Forelli's death. The Sindaccos also own Caligula's Palace, later alongside the Forelli and Leone families. The Sindacco Family wanted to do business with the Leone family and unite the two organizations and this involved DonSalvatore Leone pledging 5 million dollars to the Sindacco family. Both outfits argued over who should run the casino, and so Ken Rosenberg (once working with the Forelli Family, but then abandoned by the very powerful Vercetti Gang) was put forward as a neutral party. Ken was in the middle of the three families, so if one attacked the other, Ken would most likely be the target of revenge.

The Sindacco family was formerly represented by Johnny Sindacco, who died from shock-induced heart failure in GTA San Andreas after meeting protagonist Carl Johnson for a second time. It was revealed that Johnny had previously been captured by the San Fierro Triads, tied onto a car driven by Carl and scared into revealing information. He then went into a coma, suffering a period of psychological and physical trauma. The Introduction prequel also indicates Johnny is in fact the son of the Sindacco's Don, (who may be Paulie Sindacco), as he mentioned that his father wanted to unite their organization with the Leone family. It is probable that after the Leones abandoned Caligula's Casino and returned to Liberty City, that the Sindaccos would move in.

After their defeat by the Leone Family in the first gang war of 1998, the Sindaccos were ceased to only Torrington on Staunton Island, also starting moving into Forelli Family territory in hopes of taking it over. This resulted in the third gang war of 1998, this time between the Sindaccos and the Forellis. Franco Forelli and Paulie Sindacco attempted to establish a truce between the Forelli and Sindacco families, possibly to defeat the Leones together. Before a truce could be created, however, Toni Cipriani uses a remote control device to assume control of Paulie Sindacco's car and run over dozens of Forelli Family members with it. This fueled the Sindacco family war with the Forelli Family, which doesn't end until the assassination of Paulie Sindacco in Shoreside Vale later that same year and the death of Franco Forelli in the Little Italy explosion, all caused by Leone capo Toni Cipriani.

With no turf or front companies remaining in Liberty City, the Sindacco family have very little influence (if any at all) remaining in Liberty City by Grand Theft Auto III. The family's fate remains unknown, as their activity outside Liberty City after Paulie's death is never disclosed. It is speculated they settled permanently in Las Venturas, it being their only other known outpost.

In GTA Liberty City Stories, Sindacco members wear black shirts, black pants and brown jackets with/without sunglasses and carry pistols. In GTA San Andreas, the mobsters (presumed to be the Sindacco Family) dress in either brown leather jackets with grey pants and light blue shirts with chains, or in black jogging suits.

Trivia

The family may have just come to power in 1992 as in The Meat Business Carl mentions to Ken Rosenberg "Johnny's a done deal, and so is his gang." But the gang was still in power in Liberty City, and, as Carl had just come from Liberty City, it was highly unlikely he would not know about it.